Kaio first meets Son Goku when Goku journeys to his planet to seek his training. Kaio teaches Goku the Kaio-ken attack, which doubles the users power and a red aura which surrounds them.
Androids and Cell Saga
|“||No, that's not Krillin's move! That's the last technique Frieza used against Goku! And if Cell thinks he cannot win, he may destroy earth just like Frieza destroyed Planet Namek! That darn, Dr. Gero! How could he unleashed such an evil monster on Planet Earth.||„|
|~ King Kai in Cell's Bag of Tricks|
Before the Cell Games, Goku teleported to Kaio's place to get a better sensing range so he'd find a new guardian for the Earth. Later, during the Cell games when Cell is fighting Gohan and is caused to revert into his semi-perfect form, Cell decides to take the Earth with him and tries to self destruct. Goku makes a last second decision and teleports him to Kaio's planet where he explodes, destroys the planet and kills Goku, Kaio, Bubbles, and Gregory.
- Son Goku
- Many other alien warriors